Cell for testing fluids



Feb. 22, 1966 o. A. STEINMEYER CELL FOR TESTING FLUIDS Original FiledSept. 12, 1961- 2 Sheets-Sheet 1 IN VEN TOR. flan 4m 4 .iw/v/m 1966 0.A. STEINMEYER 3,236,094

CELL FOR TESTING FLUIDS Original Filed Sept. 12, 1961 2 Sheets-Sheet 2Hz Q 30 K 249 i g- 5 INVENTOR.

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All; W Z%% United States Patent 3,236,094 CELL FOR TESTING FLUIDS DonaldA. Steinrneyer, Orange, Calif., assignor to golufglas Aircraft Company,Inc., Santa Monica,

a r Continuation of application Ser. No. 137,687, Sept. 12, 1961. Thisapplication Mar. 5, 1965, Ser. No. 445,817 12 Claims. (Cl. 73-61) Thisis a continuation of application Serial No. 137,687 filed September 12,1961.

This invention pertains to a hydraulic testing device and moreparticularly to a testing device which utilizes a simplified method fortaking samples of fluid from a hydraulic system without contaminatingthe system.

With the increased use of hydraulic fluids in conjunction with theoperation of highly complex machinery and vehicles, such as the groundhandling equipment for a missile, it has been found necessary to developa relatively small, portable, testing device which can be introducedinto the lines of the system to take samples or specimens therefromwithout introducing contaminants. Heretofore, most testing devicesadaptable [for use with missile launch support equipment, or the like,has been relatively large and complex. This size and complexity hasrendered their use in the field relatively difiicult, if not practicallyimpossible. In addition, these devices are not generally contaminationfree, but introduce into the hydraulic system many undesirableconditions.

In the handling and launching of a missile, reliability of the missilecomponents and systems is important. Therefore, it is extremelyimportant that all reliability impairing factors such as contaminantsand impurities be kept from the components and systems.

To obviate the above noted ditficulties the present invention isrelatively small, simple in operation, and does not introduce into asystem contaminants or impurities. T o achieve this end, the presentinvention has been designed to operate through a three-step testprocedure; step one, to flush the device with filtered oil from thesystem; step tWo, to take a sample of system oil; step three, to filterthe oil and Wash and dry the device.

Basically, to achieve the above three-step test procedure, the preferredembodiment of the invention comprises a casing including a partiallythreaded bore extending longitudinally therethrough and a plurality ofports extending laterally from the bore. Inserted into the bore is aninternal body. The internal body has a metering chamber extending inwardfrom one face thereof and an indentation in each of its faces. A filterpatch assembly is mounted in the indentation in the body adjacent to themouth of the metering chamber and a test patch assembly is mounted inthe indentation in the other face and is connected to the chamber by anoutlet passage. Each of the assemblies contains a plurality of filterelements for filtering the fluid introduced into the device.

Other advantages of the invention will hereinafter become more fullyapparent from the following description of the annexed drawings whichillustrate a preferred embodiment and wherein:

FIGURE 1 is a perspective view of the test device showing itsinstallation on a portable bracket;

FIGURE 2 is a median vertical sectional view of the test device;

FIGURE 3 is a cutaway perspective view of the filter patch assemblyshowing the various filter elements;

FIGURE 4 is a cutaway perspective view of a portion of the test patchassembly showing the various filter elements; and

FIGURE 5 is a block diagram of the device showing the sequence ofoperation as a sample of fluid is taken from a hydraulic line.

.than on the other.

3,236,994 Patented Feb. 22, 1966 Referring now to the drawings whereinlike reference characters designate like or corresponding partsthroughout the several views, there is shown in FIGURE 1 the test deviceadapted for insertion into a hydraulic line. In its preferredembodiment, the device comprises a reservoir or container which includesa body or casing v12 which is mounted on a portable mounting bracket orstand 14 and has connected to its various hydraulic fittings. Thesefittings include a nipple assembly 16 inserted into a pressure port 18enabling the device to .be connected into the pressure side of thehydraulic system, and a socket assembly 20. The socket assembly 20 isconnected to the device at the return port 22 and at the inlet port 24.Said assembly 20 also includes a socket 26 for connecting the deviceinto .the return line of the system, a pair of check valves 28, 30 forcontrolling the flow of the fluid and a bleeder valve 32 (to bedescribed later). Thus the device is readily portable and is madeoperable by merely connecting the nipple assembly 16 and the socketassembly 20 into the pressure and return lines of a hydraulic system.

Referring .to FIGURE 2, in its preferred embodiment the containercomprises a generally rectangular casing or housing 12 through whichextends a longitudinal circular bore 34. Said casing has an externalthreaded portion 38 and lateral pressure and return ports 18, 22respectively. Said ports '18, 22 entered laterally from said bore 34coaxial with a common transverse axis and terminate at the exteriorsurface of said casing. The bore 34 has a threaded portion 36. Insertedinto the bore is the internal body 40. In its preferred embodiment theinternal body has a generally circular shape and is snugly inserted intothe bore. The shape of the body 40 is dictated by the shape of the bore34 which can be varied within the scope of the herein describedinvention. Circumferentially surrounding the internal body and mountedin a groove therein for sealing contact with the surface of the bore isa standard O-ring 42.

A metering chamber or cavity 44 extends into the internal body 40 from afirst transverse surface or face thereof concentric with thelongitudinal axis of the body, and terminates in a slightly inclined orconical portion 46 having an outlet passage 48 therein. Extendinglaterally from said chamber 44, each coaxial with a common transverseaxis are transverse pressure and return passages 31, 33 respectively.Said passages are aligned with said coaxial ports 18, 22 when the bodyis inserted in the bore 34 in the casing 12. The outlet passage 48extends into a transverse test patch indentation 50 formed in a secondtransverse surface or face 52 of the body. A filter patch indentation 54is formed in the wall of the chamber 44 nearest the first end 35.Inserted into the filter patch indentation and making sealing contactwith an O-ring 56 mounted in a groove in the wall thereof is the filterpatch assembly 58.

Referring to FIGURE 3, the filter patch assembly 58 is generallyring-like or cylindrical in shape and has a flanged edge 60. Theassembly includes a cartridge 62 which has a transverse section or floorsurface 64 through which extends a plurality of apertures or holes 66.The apertures are parallel with the longitudinal axis of said casing 12.The floor 64 is located transversely with respect to the cylindricalportion 68 of the cartridge 62 so that a greater portion thereof lies onone side of the floor Supported by said floor on the side thereofadjacent to the greater portion of the cylindrical portion of saidcartridge is the filter patch or cleansing filter element 70. The filterelement 70 comprises a plurality of relatively stiff support discs 72typically constructed of a fibrous paper mat with a filter disc 74maintained between. The filter disc 74 is a submicron membrane filter,such as those made from celluose material.

To maintain the filter element in contact with the floor 64 a bronzewire support 76 rests thereon flush with the surface of the flangedportion 60 of the cartridge 62. Referring to FIGURE 2, to maintain thefilter patch assembly 58, in the indentation 54, a plug 78 is threadedinto the bore 34 into contact with the flanged portion 60 of saidassembly. The plug 78 has the inlet port 24 extending therethroughparallel with the longitudinal axis .86 on the side thereof adjacent tothe cylindrical portion 87 is the test patch or sampling filter element90. Similar to the cleansing filter element 70, the sampling filterelement 90 comprises a support disc 72 in contact with the floor 86 anda filter disc 74 resting on the support disc. The retainer 82 is shapedto fit into the cylindrical cartridge 84 to make contact with a portionof the cylindrical portion 87 and with a portion of the filter disc 74thus retaining said disc in a fixed position. To retain the test patchassembly 80 in place in indentation 50 a retainer 96 is inserted intosaid indentation. Said retainer 96ha's an outlet port 98 extendingtherethrough, thus enabling fluid to pass through the test patchassembly 80 and away from the device. Circumferentially surrounding theret-ainer96 and mounted in a groove therein for sealing contact with thesurface of the indentation 50 is a standard O-ring 100. Also surroundingthe test patch cartridge 84 and mounted in a groove in indentation 50for sealing contact with the surface of the cartridge is a standardO-ring 102. To maintain the test patch assembly and retainer 96 inposition in the indentation 50 a threaded cap 104 is mated with theexternal threads 38 on the casing 12. The cap has a lip portion 106which extends into contact with a portion of the retainer 96, thusholding it and the assembly in position.

To restrain the internal body 40 from rotation after it has beeninserted into the bore 34, a pin 108 is inserted through a portion ofthe body into an aperture in the casing 12. A lock wire 110 is providedto prevent separation of the plug 78 from the casing 12 when the plug isremoved from the bore 34. Said wire 110 extends through adjacentapertures in the plug and casing thereby joining the two.

Referring to FIGURES 1 and 5, the preferred embodiment of the presentinvention operates in the following manner. To take a test sample from ahydraulic line, the nipple assembly 16 is connected into the highpressure side of the line and the socket 26 is connected into the lowpressure or return side of the line. Prior to the connecting of thedevice into the system, shutoff valve 112 is closed to prevent highpressure fluid from flowing into the device after it is connected.Therefore, after the device has been connected, fluid will flow into thedevice through the return line only as indicated by the solid arrows inFIGURE 5. Through the location of the check valves 28 and 30, fluidflows only in the direction of the arrows 114 shown on the valves. Thisresults in the fluid from the return line entering the inlet port 24,whereafter it is filtered of existing contaminants by the filter patchelement 70. The filtered fluid then passes into the metering chamber 44.As the fluid flows into the chamber 44 the bleeder valve 32 at outletport 98 is opened, enabling the fluid to flow through the test patchelement 90 and out through the outlet port 98, bleeder valve 32 andthrough a dump line 116 to a waste container 118. Thus, the first stepof the test procedure has been completed; that is, the device has beencleaned with fluid entering from the return line and filtered by thefilter patch element.

The second step is commenced by closing the bleeder valve 32 and openingthe shutoff valve 112. This introduces high pressure system oil into themetering chamber 44. The system oil is prevented from flowing up throughthe filter patch element 70 or down through the test patch element byback pressure existing in the system. After a sufficient amount of fluidhas passed through the device, as indicated by the broken arrows, theshutoff valve 112 is closed. Thereafter, the device is disconnected fromthe return line and the pressure line. The

'nipple assembly 16 and socket 26 are both stopped or closed at the sametime by suitable means to prevent leakage therefrom. This concludes thesecond step. The third step is commenced by connecting socket 26 to asolvent and nitrogen system. The solvent is of a commercial nature anddepends upon the nature of the hydraulic fluid that has been taken fromthe system. After the connection to the solvent system, the solventpasses through the test device in the same fashion as the fluid of stepone. As the solvent is .flowing through the chamber 44 the bleeder valve32is opened. The opening of the valve causes the solvent to force theoil through the test patch element 90 and out the dump line 116 and atthe same time leaches the oil out of the filter disc 74. when thesolvent flows from the dump line 116 with no indication of oil in it,the solvent is disconnected and a dry air or nitrogen source isconnected to the socket 26.

The air or nitrogen then passes through the device drying the internalparts of the device. Thereafter, to examine the filter disc 74 of testpatch element 90 and compare the resultant deposit of contaminantsthereon with known samples of contaminants, cap 104 is detached from thecasing 12 and retainer 96, permitting cartridge 84 to be removed fromindentation 50.

Thus, through the operation of the device as above described, a sampleof fluid can be taken from a highly pressurized system withoutintroducing contamination into the system. After the sample has beentaken, it can be filtered through a relatively clean test device, andthe resultant deposit of contaminants is readily accessible forcomparison with standard values. In this fashion, the above describeddevice provides a test procedure readily adapted to field and laboratoryuses.

I claim: 7

1. A cell "for testing liquids comprising: a casing including apartially threaded bore extending longitudinally therethrough, aplurality of pressure and return ports extending laterally from saidbore coaxial with a common transverse axis; an internal body includingfirst and second transverse surfaces, coaxial transverse pressureandreturn passages, a longitudinal outlet passage, a central longitudinalmetering chamber extending from said first transverse surface to oneextremity of said outlet passage, a test patch indentation in saidsecond transverse surface and a filter patch indentation in the Wall ofsaid chamber immediately adjacent to said first transverse surface, saidbody being adapted to be inserted into the bore of said casing wherebysaid pressure and return ports and passages are aligned; a filter patchassembly adapted to be inserted into said filter patch indentation toclose said chamber, said assembly including a supporting member having atransverse section containing a plurality of holes parallel with thelongitudinal axis of said body, and a filter element in contact withsaid thin transverse section on the side thereof opposite to saidchamber; a plug member having a portion thereof insertable into the borein said casing and engageable with said threaded portion therein and aninlet port extending through said plug parallel with the longitudinalaxis of said casing; a test patch assembly insertable into saidtestpatch indentation, said assembly including a supporting memberengageable with the walls of said indentation including a transversesection containing a plurality of holes parallel with the longitudinalaxis of said body and a cylindrical flanged portion, a test filterelement in contact with said transverse section on the side thereofadjacent to said flange portion and a first retainer adapted to holdsaid element in contact with said transverse section, said firstretainer having a portion thereof in contact with said outlet passageand said flanged portion; a second retainer engageable with a portion ofsaid test patch indentation to retain said test filter assembly in afixed position, said second retainer containing a central longitudinaloutlet port adapted to flow fluid out of said chamber; and a capengageable with the external thread on said casing to secure said secondretainer in position and permit disassembly of said cell for examinationof said test filter element.

2. A cell for testing liquids comprising: a casing including a partiallythreaded bore extending longitudinally therethrough, a plurality ofpressure and return ports extending laterally from said bore coaxialwith a common transverse axis; an internal body including a first andsecond transverse surface, transverse pressure and return passages, .alongitudinal outlet passage and a central longitudinalmetering chamberextending from said first transverse surface to one extremity of saidoutlet passage, a test patch indentation in said second transversesurface and a filter patch indentation in the Wall of said chamberimmediately adjacent to said first transverse surface, said of saidbody, and a filter element in contact with said transverse section onthe side thereof opposite to said chamber; a plug member having aportion thereof insertable into the chamber in said casing andengageable with said thread portion therein and an inlet port extendingtherethrough parallel with the longitudinal axis of said casing; a testpatch assembly insertable into said test patch indentation, saidassembly including a supporting member engageable with the walls of saidindentation including a transverse section containing a plurality ofholes parallel with the longitudinal axis of said body and a cylindricalflanged portion, a test filter element in contact with said transversesection on the side thereof adjacent to said flanged portion and a firstretainer adapted to hold said element in contact with said transversesection, said first retainer having a portion in contact with saidoutlet passage and said flanged portion; a second retainer engageablewith a portion of said test patch indentation to retain said test filterassembly in a fixed position, said second retainer including a centrallongitudinal outlet port adapted to flow fluid out of said chamber; anda cap engageable with the external thread on said casing to secure saidsecond retainer in position and permit disassembly of said cell forexamination of said test filter element whereby the contaminants andimpurities in a hydraulic system can be readily determined.

3. Means for testing liquids comprising: a container having a liquidreceiving chamber therein, a pressure port, a return port, an inlet portand an outlet port; a cleansing filter mounted in said chamber acrossthe inlet port to cleanse liquid introduced into said chamber by saidinlet port; a testing filler mounted in said chamber across the outletport to test-filter liquid introduced into said chamber by said pressureport; means for selectively connecting a high pressure side of ahydraulic system to said pressure port; means for selectively connectinga low pressure side of the system to said return port and including acheck valve for preventing liquid flow towards said return port; meansfor selectively connecting the low pressure side of the system to saidinlet port and including a check valve for preventing liquid flow awayfrom said inlet port; and means for selectively connecting a dump lineto said outlet port whereby a sample of liquid can be taken from thehydraulic system and tested for impurities without introducingcontaminants into said system by selectively operating all of saidconnecting means in a predetermined sequence of flushing said chamberwith cleansed liquid from the system, taking a sample of system liquid,and test filtering the sample for obtaining a collection of impuritieson said testing filter.

4. A cell for testing liquids comprising: a casing; a liquid containingmeans adapted to be inserted in said casing for containing a sample ofliquids; flow means in said casing and said containing means adapted toallow liquid to flow into and out of said containing means; connectingmeans attached to said flow means for selectively connecting said cellinto a hydraulic system; cleansing filter meansmounted to saidcontaining means in contact with one end thereof to cleanse liquid as itflows through said cleansing filter means into said containing means;test .fil-ter means mounted to said containing means in contact with theother end thereof to test-filter liquid as it flows through said testfilter means out of'said containing means; inlet means for selectivelyconnecting said cleansing filter means to said hydraulic system; andoutlet means for selectively connecting said test filter means to a dumpline, whereby a sample of liquid can be taken from the hydraulic systemand testedfor impurities without introducing contaminants 'intosaidsystem'by selectively operating said connecting means, said inlet meansand said outlet means in a predetermined sequence of flushing said cellwith cleansed liquid from the system, taking a sample of system liquid,and test filtering the sample for obtaining a collection of impuritieson said test filter means.

5. Apparatus as defined in claim 4 wherein said cleansing and testfilter means each includes an assembly comprising at least onerelatively stiff, liquid permeable support sheet member and onesubmicron membrane filter sheet member in contiguous contact with saidsupport sheet member.

6. A cell for testing liquid comprising: a casing having a longitudinalbore, means defining a first pressure port and means defining a firstreturn port in said casing communicating with said longitudinal bore; aninternal body having a central longitudinal chamber open at one endthereof and a passage and indentation communicating with the chamber atthe other end, means defining a second pressure port and means defininga second return port, said second pressure and return ports connectingwith said chamber and said body being adapted to be inserted into saidlongitudinal bore to align said first pressure and return ports in saidcasing respectively with said second pressure and return ports in saidbody; cleansing filter means in contact with a portion of said internalbody and adapted to close the one end of said. chamber; tes-t filtermeans adapted to be inserted into said indentation for closing thepassage communicating with said chamber; and means for connecting saidcell into a hydraulic system, including means for selectively connectingsaid first pressure port to a high pressure line of the system, meansfor selectively connecting said first return port and said cleansingfilter means to a low pressure line of the system, and means forselectively connecting said test filter means to a dump line whereby asample of liquid can be taken from the hydraulic system and tested forimpurities without introducing contaminants into said system byselectively operating said connecting means in a predetermined sequenceof flushing said cell with cleansed liquid from the system, taking asample of system liquid, and test filtering the sample for obtaining acollection of impurities on said test filter means.

7. Apparatus as defined in claim 6 wherein said cleansing and testfilter means each includes an assembly comprising a cartridge having aperforated floor and at least one relatively stifi fibrous support discand one submicron membrane filter disc which is supported by said floor.

8. Means for testing liquids comprising: a container including a liquidreceiving chamber therein, a pressure port, a return port, an inlet portand an outlet port; a cleansing filter mounted in said container acrossa liquid flow path from said inlet port to said chamber, for cleansingliquid being introduced into said chamber by said inlet port; a testingfilter mounted in said container across a liquid flow path from saidchamber to said outlet port, to test-filter liquid introduced into saidchamber by said pressure port; means for selectively connecting a highpressure side of a hydraulic system to said pressure port; means forselectively connecting a low pressure side of the system to said returnport and including check valve means for preventing liquid flow towardssaid return port into said chamber; means for selectively connecting asource of solvent to said inlet port and including check valve means forpreventing liquid flow out of said chamber and away from said inletport; and means for selectively connecting a dump line to said outletport, whereby a sample of liquid can be taken from the hydraulic systemand tested for impurities without introducing contaminants into saidsystem by selectively operating all of said connecting means in apredetermined sequence of taking a sample of system liquid into saidchamber, test filtering the sample through said testing filter, andpassing solvent through said cleansing filter, chamber and testingfilter to obtain a readily visible collection of impurities on saidtesting filter.

9. A cell for testing liquids comprising: a casing including a liquidcontaining chamber therein for containing a sample of liquid; flow meansin said casing adapted to allow liquid to flow into and out of saidchamber; connecting means attached to said flow means for selectivelyconnecting said cell into a hydraulic system; cleansing filter meansmounted to said casing in communication with one end of said chamber tocleanse liquid as it flows through said cleansing filter means intosaid. chamber; test filter means mounted to said casing in communicationwith another end of said chamber to test-filter liquid as it flows outof said chamber through said test filter means; inlet means forselectively connecting said cleansing filter means to a source ofsolvent; and outlet means for selectively connecting said test filtermeans to a dump line, whereby a sample of liquid can be taken from thehydraulic system and tested. for impurities without introducingcontaminants into said system by selectively operating said connectingmeans, said inlet means and said outlet means in a predeterminedsequence of taking a sample of system liquid into said chamber, testfiltering the sample through said test filter means, and passing solventthrough said cleansing filter means, chamber and test filter means toobtain a readily visible collection of impurities on said test filtermeans.

10. Apparatus as defined in claim 9 wherein said cleansing and testfilter means each includes an assembly comprising at least onerelatively stiif, liquid permeable support sheet member and onesubmicron membrane filter sheet member in contiguous contact with saidsupport sheet member.

11. A cell for testing liquids comprising: a casing including alongitudinal chamber therein, means defining a pressure port, meansdefining a return port, means defining an inlet port and means definingan outlet port, said pressure and return ports in said casingcommunicating laterally with-said chamber and said inlet and outletports in said casing communicating longitudinally with respective endsof said chamber; cleansing filter means mounted in said casing and.disposed across a liquid flow path from said inlet port to itsassociated end of said chamber, for cleansing liquid being introducedinto said chamber by said inlet port; test filter means mounted in saidcasing and disposed across a liquid flow path from the other end of saidchamber to said outlet port; and means for connecting said cell into ahydraulic system, including means for selectively connecting saidpressure port to a high pressure line of the system, means forselectively connecting said return port means to a low pressure line ofthe system, means for selectively connecting a source of solvent to saidinlet port, andmeans for selectively connecting said test filter meansto a dump line whereby a sample of liquid. can be taken from thehydraulic system and tested for impurities without introducingcontaminants into said system by selectively operating said connectingmeans in a predetermined sequence of taking a sample of system liquidinto said chamber, test-filtering the sample through said test filtermeans, and passing solvent through said cleansing filter means, chamberand test filter means to obtain a readily visible collection ofimpurities on said .test filter means.

12. Apparatus as defined in claim 11 wherein said cleansing and testfilter means each includes an assembly comprising a cartridge having aperforated floor and at least one relatively stilt fibrous support discand one submicron'membrane filter disc which are supported by saidfloor.

No references cited.

LOUIS R. PRINCE, Primary Examiner.

1. A CELL FOR TESTING LIQUIDS COMPRISING: A CASING INCLUDING A PARTIALLYTHREADED BORE EXTENDING LONGITUDINALLY THERETHROUGH, A PLURALITY OFPRESSURE AND RETURN PORTS EXTENDING LATERALLY FROM SAID BORE COAXIALWITH A COMMON TRANSVERSE AXIS; AN INTERNAL BODY INCLUDING FIRST ANDSECOND TRANSVERSE SURFACES, COAXIAL TRANSVERSE PRESSURE AND RETURNPASSAGES, A LONGITUDINAL OUTLET PASSAGE, A CENTRAL LONGITUDINAL METERINGCHAMBER EXTENDING FROM SAID FIRST TRANSVERSE SURFACE TO ONE EXTREMITY OFSAID OUTLET PASSAGE, A TEST PATCH INDENTATION IN SAID SECOND TRANSVERSESURFACE AND A FILTER PATCH INDENTATION IN THE WALL OF SAID CHAMBERIMMEDIATELY ADJACENT TO SAID FIRST TRANSVERSE SURFACE, SAID BODY BEINGADAPTED TO BE INSERTED INTO THE BORE OF SAID CASING WHEREBY SAIDPRESSURE AND RETURN PORTS AND PASSAGES ARE ALIGNED; A FILTER PATCHASSEMBLY ADAPTED TO BE INSERTED INTO SAID FILTER PATCH INDENTATION TOCLOSE SAID CHAMBER, SAID ASSEMBLY INCLUDING A SUPPORTING MEMBER HAVING ATRANSVERSE SECTION CONTAINING A PLURALITY OF HOLES PARALLEL WITH THELONGITUDINAL AXIS OF SAID BODY, AND A FILTER ELEMENT IN CONTACT WITHSAID THIN TRANSVERSE SECTION ON THE SIDE THEREOF OPPOSITE TO SAIDCHAMBER; A PLUG MEMBER HAVING A PORTION THEREOF INSERTABLE INTO THE BOREIN SAID CASING AND ENGAGEABLE WITH SAID THREADED PORTION THEREIN AND ANINLET PORT EXTENDING THROUGH SAID PLUG PARALLEL WITH THE LONGITUDINALAXIS OF SAID CASING; A TEST PATCH ASSEMBLY INSERTABLE INTO SAID TESTPATCH INDENTATION, SAID ASSEMBLY INCLUDING A SUPPORTING MEMBERENGAGEABLE WITH THE WALLS OF SAID INDENTATION INCLUDING A TRANSVERSESECTION CONTAINING A PLURALITY OF HOLES PARALLEL WITH THE LONGITUDINALAXIS OF SAID BODY AND A CYLINDRICAL FLANGED PORTION, A TEST FILTERELEMENT IN CONTACT WITH SAID TRANSVERSE SECTION ON THE SIDE THEREOFADJACENT TO SAID FLANGE PORTION AND A FIRST RETAINER ADAPTED TO HOLDSAID ELEMENT IN CONTACT WITH SAID TRANSVERSE SECTION, SAID FIRSTRETAINER HAVING A PORTION THEREOF IN CONTACT WITH SAID OUTLET PASSAGEAND SAID FLANGED PORTION; A SECOND RETAINER ENGAGEABLE WITH A PORTION OFSAID TEST PATCH INDENTATION TO RETAIN SAID TEST FILTER ASSEMBLY IN AFIXED POSITION, SAID SECOND RETAINER CONTAINING A CENTRAL LONGITUDINALOUTLET PORT ADAPTED TO FLOW FLUID OUT OF SAID CHAMBER; AND A CAPENGAGEABLE WITH THE EXTERNAL THREAD ON SAID CASING TO SECURE SAID SECONDRETAINER IN POSITION AND PERMIT DISASSEMBLY OF SAID CELL FOR EXAMINATIONOF SAID TEST FILTER ELEMENT.